#include "cuda_runtime.h"
#include "device_launch_parameters.h"
#include "cuPrintf.cuh"
#include <stdio.h>

cudaError_t addWithCuda(int *c, const int *a, const int *b, size_t size);

__global__ void addKernel2(int *c, const int *a, const int *b);
__global__ void addKernel(int *c, const int *a, const int *b)
{
    int i = threadIdx.x;
    c[i] = a[i] * b[i];
	cuPrintf("Value is: %d\n", i);
}

#define cudaErrorGuard(error, exit, message, ...) if ((error) != cudaSuccess) { fprintf(stderr, message, __VA_ARGS__); fprintf(stderr, "\n"); exit; }
#define cudaErrorGuardAuto(error, exit) cudaErrorGuard(error, exit, cudaGetErrorString(error))

int main()
{
    const int arraySize = 5;
    const int a[arraySize] = { 1, 2, 3, 4, 5 };
    const int b[arraySize] = { 10, 20, 30, 40, 50 };
    int c[arraySize] = { 0 };
	cudaError_t cudaStatus;	

    // Add vectors in parallel.
    cudaErrorGuard(cudaStatus = addWithCuda(c, a, b, arraySize), return 1, "addWithCuda failed!");
	//cudaPrintfDisplay(stdout, true);
	
    printf("{1,2,3,4,5} + {10,20,30,40,50} = {%d,%d,%d,%d,%d}\n", c[0], c[1], c[2], c[3], c[4]);

    // cudaDeviceReset must be called before exiting in order for profiling and tracing tools such as Nsight and Visual Profiler to show complete traces.
    //cudaPrintfEnd();
	cudaErrorGuard(cudaStatus = cudaDeviceReset(), return 1, "cudaDeviceReset failed!");

	fprintf(stderr, "\n");
    return 0;
}

// Helper function for using CUDA to add vectors in parallel.
cudaError_t addWithCuda(int *c, const int *a, const int *b, size_t size)
{
    int *dev_a = 0;
    int *dev_b = 0;
    int *dev_c = 0;
    cudaError_t cudaStatus;

    // Choose which GPU to run on, change this on a multi-GPU system.
    cudaErrorGuard(cudaStatus = cudaSetDevice(0), goto Error, "cudaSetDevice failed!  Do you have a CUDA-capable GPU installed?");
	cudaErrorGuardAuto(cudaStatus = cudaPrintfInit(), goto Error);

    // Allocate GPU buffers for three vectors (two input, one output).
    cudaErrorGuard(cudaStatus = cudaMalloc((void**)&dev_c, size * sizeof(int)), goto Error, "cudaMalloc failed!");
    cudaErrorGuard(cudaStatus = cudaMalloc((void**)&dev_a, size * sizeof(int)), goto Error, "cudaMalloc failed!");
    cudaErrorGuard(cudaStatus = cudaMalloc((void**)&dev_b, size * sizeof(int)), goto Error, "cudaMalloc failed!");

    // Copy input vectors from host memory to GPU buffers.
    cudaStatus = cudaMemcpy(dev_a, a, size * sizeof(int), cudaMemcpyHostToDevice); cudaErrorGuard(cudaStatus, goto Error, "cudaMemcpy failed!");
    cudaStatus = cudaMemcpy(dev_b, b, size * sizeof(int), cudaMemcpyHostToDevice); cudaErrorGuard(cudaStatus, goto Error, "cudaMemcpy failed!");

    // Launch a kernel on the GPU with one thread for each element.
    addKernel2<<<1, size>>>(dev_c, dev_a, dev_b);

    // cudaDeviceSynchronize waits for the kernel to finish, and returns any errors encountered during the launch.
    cudaErrorGuard(cudaStatus = cudaDeviceSynchronize(), goto Error, "cudaDeviceSynchronize returned error code %d after launching addKernel!\n", cudaStatus);

    // Copy output vector from GPU buffer to host memory.
    cudaErrorGuard(cudaStatus = cudaMemcpy(c, dev_c, size * sizeof(int), cudaMemcpyDeviceToHost), goto Error, "cudaMemcpy failed!");

Error:
    cudaFree(dev_c);
    cudaFree(dev_a);
    cudaFree(dev_b);
    
    return cudaStatus;
}
